42921913 has 2 divisors, whose sum is σ = 42921914. Its totient is φ = 42921912.

The previous prime is 42921899. The next prime is 42921917. The reversal of 42921913 is 31912924.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40602384 + 2319529 = 6372^2 + 1523^2 .

It is a cyclic number.

It is not a de Polignac number, because 42921913 - 2⁵ = 42921881 is a prime.

It is not a weakly prime, because it can be changed into another prime (42921917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21460956 + 21460957.

It is an arithmetic number, because the mean of its divisors is an integer number (21460957).

Almost surely, 2^42921913 is an apocalyptic number.

It is an amenable number.

42921913 is a deficient number, since it is larger than the sum of its proper divisors (1).

42921913 is an equidigital number, since it uses as much as digits as its factorization.

42921913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 31.

The square root of 42921913 is about 6551.4817407973. The cubic root of 42921913 is about 350.1276078910.

It can be divided in two parts, 42921 and 913, that added together give a palindrome (43834).

The spelling of 42921913 in words is "forty-two million, nine hundred twenty-one thousand, nine hundred thirteen".